import java.util.Scanner;

public class Main1607 {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
            int a= sc.nextInt();
            int x=a/10;
            int y=a%10;
            double b=x*1.0/y;
            System.out.println(String.format("%.1f",b ));
    }
}
